There has been known various buckles each provided with a device for adjusting length of a personal adornment band such as a wristwatch and a bracelet. A publication of Japanese Utility Model No. 2582413 discloses a triple-folded buckle for a watchband where length thereof is adjusted in a longitudinal direction of the band.
The triple-folded buckle is housed in a surface cover and is provided with an adjusting device retractable in the surface cover. A pair of pushbuttons retractable in a lateral direction of the band is further provided in the surface cover. The pushbuttons are urged by a spring so as to project out of the surface cover. An engagement member of each push button thus urged engages with one of consecutive engaging teeth formed in length adjusting plate so that the movement of the length adjusting plate is restricted.
When the pushbuttons are depressed with fingers against the urging of the spring, the engagement member is released from the engagement teeth, thereby to enable the length adjusting plate to be retracted in the surface cover or projected therefrom. When the fingers are released from the pushbuttons, the pushbuttons are urged by the spring so as to be moved outward and again abut against the length adjusting plate. Thus, the length adjusting plate is stopped.
The triple-folded buckle is thus advantageous in arbitrarily adjusting the position of the buckle in the longitudinal direction of the band.
However, in the buckle disclosed in Japanese Utility Model No. 2582413, the pushbuttons may be pushed toward the surface cover when the wrist is inwardly bent. Accordingly, the length adjusting plate is accidentally moved in spite of the intension of the wearer. More particularly, when the length adjusting plate is accidentally pulled out from the surface cover, the watch is disengaged from the wrist and falls off.
There has recently been commonly used a lock device for locking a triple-folded buckle in a closed position, as shown in Japanese Patent Application Laid-Open No. 10-327914, where a pair of pushbuttons retractable in a lateral direction of the band are provided in a surface cover. The lock device is released when the pushbuttons are depressed so that the buckle opens from the closed position.
When such a lock device is provided in the surface cover with the length adjusting device, it becomes difficult to distinguish the pushbuttons for the lock device from those of the length adjusting device so that erroneous operations tends to occur.
A first object of the present invention is to provide a device for adjusting length where a length adjusting plate is prevented from becoming accidentally disengaged which causes personal adornment band to be loosened.
A second object of the present invention is to provide a device for adjusting length where mishandling by a user is prevented and the operability of the device is improved.